Marginal accuracy of interim restorations fabricated from four interim autopolymerizing resins.
STATEMENT OF PROBLEM: One of the most important requirements for interim restorations is good marginal adaptation. Polymerization shrinkage of interim restorative materials can jeopardize the marginal integrity of interim restorations. PURPOSE: The purpose of this study was to compare the marginal accuracy of interim restorations made with 4 interim materials. MATERIAL AND METHODS: A direct technique was used to fabricate 44 interim restorations with 4 materials: Protemp 3 Garant, Trim II, Tempron, and Acropars (n=11). The interim restorations were made on a prepared molar-shaped metal die with a vinyl polysiloxane impression as a matrix. Marginal discrepancy of interim restorations was measured at the midpoint of buccal, palatal, mesial, and distal surfaces of metal die finish line with a microscope at x100 magnification. Comparisons were made with 1-way analysis of variance and the Duncan multiple range test (alpha=.05). RESULTS: The mean marginal discrepancies of Protemp 3 Garant, Trim II, Tempron, and Acropars were 0.059, 0.063, 0.068, and 0.102 mm, respectively. Acropars exhibited the most marginal discrepancies and was significantly different from the other materials tested (P<.001). However, there were no statistical differences between the other 3 materials tested. CONCLUSIONS: Interim restorations made from the Bis-GMA and conventional acrylic resins tested produced comparable marginal fit. Acropars demonstrated significant increases in marginal gap size.